毛细管区带电泳法测定尿中甲酸含量

采用高效毛细管区带电泳法测定人体尿中甲酸含量,尿样经过滤后直接进样,方法简单、快速,测定结果令人满意。电泳电解质体系采用５ｍｍｏｌ／Ｌ邻苯二甲酸氢钾,０．５ｍｍｏｌ／Ｌ十六烷基三甲基溴化铵,ｐＨ６,５０ｃｍ×５０μｍｉ．ｄ．熔融石英毛细管（有效长度４８．５ｃｍ）,检测波长２１０ｎｍ,负电源,分离电压３０ｋＶ,压力进样,恒温２５℃,每次电泳前用０．１ｍｏｌ／ＬＮａＯＨ及缓冲溶液对毛细管各冲洗５ｍｉｎ。同时,采用检测波长与参比波长对调的方法使负峰转变为正峰。     

九种嘌呤碱的毛细管区带电泳分离

用毛细管区带电泳法分离和测定咖啡碱，９－Ｎ二羟丙基茶碱，可可碱，腺嘌呤，鸟嘌呤、茶碱、黄嘌呤、尿酸和６－巯基嘌呤，在熔硅毛细管（７０ｃｍ×７５μｍｉ．ｄ，有效长度６３ｃｍ）内，使用０．０１ｍｏｌ／Ｌ（ｐＨ＝１０）硼砂缓冲溶液，电压为２５ｋＶ温度为３０℃，真空进样１ｓ，于２６０ｎｍ处检测，可在７ｍｉｎ内分离上述到９种嘌呤碱，理论塔板数达到３．０×１０＾５，检测限达ｆｍｏｌ级，方法用于人尿分析，结果令     

毛细管区带电泳分离和测定嘧啶碱

本报道毛细管区带电泳分离和测定胞嘧啶，胸腺嘧啶，尿嘧啶，羟乙基氟尿嘧啶，尿嘧啶丙酸和５－氟尿嘧啶，在熔硅毛细管（７０ｃｍ×７５μｍｉ，ｄ，有效长度６３ｃｍ）上，以０．０１ｍｏｌ／Ｌ硼砂缓冲溶液（ｐＨ＝９．２５）作电解质，电压为２０ｋＶ，温度为３５℃，真空进样１ｓ，于２７０ｎｍ处检测，可在８ｍｉｎ内完全分离上述６种嘧啶碱，塔板数达到２．５×１０＾５，碱基检测限为（０．９～３．６）×１０＾－６ｍｏｌ     

吸附伏安法测定中草药中的钼

叙述了测定痕量钼的一种灵敏的吸附伏安法。本法以钼（Ⅵ）和茜素红络合物在悬汞电极上的吸附行为为基础，在０．０１ｍｏｌ／ＬＮａＡｃ、０．０８ｍｏｌ／ＬＨＡｃ和１．５×１０－６ｍｏｌ／Ｌ茜素红底液条件下，该体系１．５、２．５阶微分吸附伏安法的线性范围是７．５×１０－１１～７．５×１０８ｍｏｌ／Ｌ；对２．５阶微分吸附伏安法，富集３ｍｉｎ的检测下限是５×１０－１１ｍｏｌ／Ｌ。用此法直接测定了中草药中的痕量钼。     

复方新诺明片剂中有效成分的毛细管区带电泳快速测定法

研究了用毛细管区带电泳法快速测定复方新诺明片中磺胺甲恶唑（ＳＭＺ）和甲氧苄氨嘧啶（ＴＭＰ）的含量。使用长２７ｃｍ（有效长度２０ｃｍ）内径５０μｍ的石英毛细管,２５ｋＶ分离电压,在０．０５ｍｏｌ／Ｌ的乙酸盐缓冲液（ｐＨ５．５）中,上述两组分可在１．５ｍｉｎ内完全分离。用紫外检测器在２１４ｎｍ处检测,外标法定量。１０次检测含有１４１．７ｍｇ／ＬＳＭＺ和２５．６ｍｇ／ＬＴＭＰ的试样溶液,相对标准偏差为１     

毛细管电泳在拮抗药物对氨基苯甲酸，对羟基苯甲酸和磺胺分析测…

本报道了一种用毛细管区带电泳法分离与测定对氨基苯甲酸、对羟基苯甲酸及磺胺类药物的新方法。电泳条件为：用２０ｍｍｏｌ／Ｌ硼砂－２０ｍｍｏｌ／ＬＨ３ＰＯ４－２０ｍｍｏｌ／Ｌβ－环糊精－４％乙醇作电泳液，Ｌ－抗坏血酸为内标，２８０ｎｍ为检测波长，样品由电进样方式１０ｋＶ／１０ｓ）引入毛细管（５１．２ｃｍ×５０μｍｉ．ｄ．，有效分离长度为３８．５ｃｍ）．在２４．５℃下，６ｍｉｎ内三可达基线分离（电泳电     

铂－锇共显色衍生配合物的高效液相色谱研究

研究了Ｏｓ（Ⅱ）和４，４’二（二乙氨基）苯硫酮与Ｐｔ（Ⅱ）共显色所衍生的配合物，于ＮｕｃｌｅｏｓｉｌＣ＿８柱上，用含３×１０￣（－３）ｍｏｌ／ＬＤＬ－樟脑－１０－磺酸和０．０２ｍｏｌ／ＬＨＡｃ－ＮａＡｃ（ｐＨ３．５）的乙腈－丙酮－水（７２：５：２３，Ｖ／Ｖ）作流动相（１．０ｍＬ／ｍｉｎ）分离并检测。线性范围为０．２～４．０μｇ／ｍＬＰｔ；检测限为１．０ｎｇＰｔ。此方法已应用于抗癌药物顺铂和卡铂的分析。     

铂—钯共显色衍生络合物的高效液相色谱研究

研究了Ｐｄ（Ⅱ）和４，４＇－二（二乙氨基）苯硫酮（ＢＤＰＴＫ）共显色所生成的Ｐｔ（Ⅱ）络合物，于Ｎｕｃｌｅｏｓｉｌ Ｃ８柱上，用含３×１０＾－３ｍｏｌ／Ｌ ＣＳＡ和０．０２ｍｏｌ／Ｌ ＨＡｃ－ＮａＡｃ（ｐＨ３．５）的乙腈－丙酮－水（７２：５：２３，Ｖ／Ｖ）作流动相（１．０ｍｌ／ｍｉｎ）分离并检测。Ｐｔ的校正曲线的线性范围为０．２～３．０μｇ／ｍｌ，Ｐｔ检测限为０．７ｎｇ。此方法已应用于抗癌药物顺铂     

新型安培检测毛细管电泳微系统

将电极、６ｃｍ分离毛细管、缓冲池、检测池集成于８．４×５．０ｃｍ有机玻璃片上,制作了一个毛细管电泳微系统。以碳纤维微盘电极作为工作电极,采用三电极体系柱端检测了１×１０－４ｍｏｌ／Ｌ多巴胺（ＤＡ）,具有良好的重现性,检测限３．６×１０－８ ｍｏｌ／Ｌ,线性范围５×１０－７～１×１０－４ｍｏｌ／Ｌ,并在该系统上分离了邻苯二酚（ＣＡ）和多巴胺的混合物。     

高效液相色谱法测定人血浆中甲磺酸培氟沙星浓度

建立了一种测定人血浆中甲磺酸培氟沙星的匠相液相色谱方法,用的是ＺｏｒｂａｘＯＤＳＣ＿（１８）柱和用三乙醇胺调节成ｐＨ为３．０的甲醇－０．０４ｍｏｌ／ＬＨ＿３ＰＯ＿４溶液（８０：２０,Ｖ／Ｖ）的流动相,检测在２７６ｎｍ处进行,流量为１ｍＬ／ｍｉｎ,线性范围是６．０１×１０￣（－８）～３．０１×１０￣（－５）ｍｏｌ／Ｌ（γ＝０．９９９８）,检测极限为６．０１×１０￣（－８）ｍｏｌ／Ｌ,平均回收率为９７．５７±３．０４％,日内与日间的ＣＶ分别为３．２９％和５．０８％。     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.